Community Cards
The five shared cards dealt face up in the middle of the table that every player can use.
Community cards arrive in three stages: the flop (three cards), the turn (one card) and the river (one card). Together they are called the board.
Because everyone shares them, reading the community cards is the core skill of Hold'em. Ask what the best possible hand is, which draws are present, and how your hand compares.
Example
The board reads Q9472. Any player holding a Queen has at least top pair.